* broken maxcpus in 2.4.24
@ 2004-02-02 23:37 Dan Christian
2004-02-03 8:53 ` Marc-Christian Petersen
2004-02-03 23:45 ` James Schmidt
0 siblings, 2 replies; 4+ messages in thread
From: Dan Christian @ 2004-02-02 23:37 UTC (permalink / raw)
To: linux-kernel
I compiled a vanilla 2.4.24 for a 2 processor Xeon.
I set CONFIG_NR_CPUS to 4 (2 CPUs x 2 hyperthreads each).
When I boot the kernel, /proc/cpuinfo only shows 2 cpus (0-1) and
performance is bad.
I reconfigure CONFIG_NR_CPUS back to 32. Now it shows 4 cpus (0-3) and
performance is normal.
Is this a bug or am misunderstanding how to set this configuration
variable?
-Dan Christian
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: broken maxcpus in 2.4.24
2004-02-02 23:37 broken maxcpus in 2.4.24 Dan Christian
@ 2004-02-03 8:53 ` Marc-Christian Petersen
2004-02-03 23:45 ` James Schmidt
1 sibling, 0 replies; 4+ messages in thread
From: Marc-Christian Petersen @ 2004-02-03 8:53 UTC (permalink / raw)
To: linux-kernel; +Cc: Dan Christian
On Tuesday 03 February 2004 00:37, Dan Christian wrote:
Hi Dan,
> I compiled a vanilla 2.4.24 for a 2 processor Xeon.
> I set CONFIG_NR_CPUS to 4 (2 CPUs x 2 hyperthreads each).
> When I boot the kernel, /proc/cpuinfo only shows 2 cpus (0-1) and
> performance is bad.
> I reconfigure CONFIG_NR_CPUS back to 32. Now it shows 4 cpus (0-3) and
> performance is normal.
> Is this a bug or am misunderstanding how to set this configuration
> variable?
http://linux.bkbits.net:8080/linux-2.4/cset@1.1136.1.68?nav=index.html|
ChangeSet@-12w
ciao, Marc
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: broken maxcpus in 2.4.24
2004-02-02 23:37 broken maxcpus in 2.4.24 Dan Christian
2004-02-03 8:53 ` Marc-Christian Petersen
@ 2004-02-03 23:45 ` James Schmidt
2004-02-03 23:49 ` Dave Jones
1 sibling, 1 reply; 4+ messages in thread
From: James Schmidt @ 2004-02-03 23:45 UTC (permalink / raw)
To: linux-kernel
Hope this hasn't been posted already.
Not sure if I am right or not on this but this seems to be related, at
least on my box, to the APIC IDs of the CPUs. I am using an Intel
SE7500CW, populated with 2x XEONs. The APIC ID's of the CPUs are 0 & 1
for the first physical CPU, and 6 & 7 for the second physical CPU (don't
ask me why). If I don't use NR_CPUs = 8, I don't seem to see the second
physical CPU. Someone correct me if I'm wrong.
-James
On Mon, 2 Feb 2004, Dan Christian wrote:
> I compiled a vanilla 2.4.24 for a 2 processor Xeon.
>
> I set CONFIG_NR_CPUS to 4 (2 CPUs x 2 hyperthreads each).
>
> When I boot the kernel, /proc/cpuinfo only shows 2 cpus (0-1) and
> performance is bad.
>
> I reconfigure CONFIG_NR_CPUS back to 32. Now it shows 4 cpus (0-3) and
> performance is normal.
>
> Is this a bug or am misunderstanding how to set this configuration
> variable?
>
> -Dan Christian
>
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2004-02-03 23:51 UTC | newest]
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2004-02-02 23:37 broken maxcpus in 2.4.24 Dan Christian
2004-02-03 8:53 ` Marc-Christian Petersen
2004-02-03 23:45 ` James Schmidt
2004-02-03 23:49 ` Dave Jones
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